Do Lacto-Ovo Vegetarians Need Supplements?

December 2, 2025 •

4 min read

While a well-planned lacto-ovo vegetarian diet can be highly nutritious, studies have shown that some individuals still exhibit lower levels of certain key nutrients compared to omnivores. So, do lacto-ovo vegetarians need supplements? The answer depends heavily on the individual's dietary choices and lifestyle, with careful attention required for vitamin B12, vitamin D, iron, zinc, and omega-3 fatty acids.

Quick Summary

This article explores potential nutrient gaps in a lacto-ovo vegetarian diet, highlighting the need for vigilance with certain vitamins and minerals. It details which nutrients may require supplementation and how to optimize dietary intake for optimal health.

Key Points

B12 supplementation is vital: Despite consuming dairy and eggs, lacto-ovo vegetarians often have lower vitamin B12 levels and should use fortified foods or a supplement regularly.
Monitor Vitamin D levels: While fortified foods exist, sun exposure and geographical location impact Vitamin D synthesis, making a supplement a common recommendation for many.
Enhance plant-based iron absorption: Consuming iron-rich plant foods with Vitamin C can significantly increase the absorption of non-heme iron, which is less bioavailable than animal-sourced iron.
Address potential zinc challenges: Phytates in many plant foods can inhibit zinc absorption, so dietary strategy or potential supplementation should be considered, particularly if intake is low.
Consider algal oil for omega-3s: Since the conversion of plant-based ALA to beneficial EPA and DHA is inefficient, an algal oil supplement is the most direct way to secure these fatty acids.

A lacto-ovo vegetarian diet, which includes dairy and eggs, offers a more diverse range of nutrients than a vegan diet, which excludes all animal products. However, simply including these two food groups does not automatically guarantee a nutritionally complete diet. Several key nutrients require careful attention, and supplementation may be necessary for optimal health, particularly for those with a limited dietary intake or specific health conditions. This article provides a comprehensive overview of the nutrients to monitor and strategies for ensuring adequacy.

Potential Nutrient Deficiencies for Lacto-Ovo Vegetarians

While dairy and eggs are excellent sources of protein, calcium, and vitamin D, they might not be enough to cover all nutritional bases, and the bioavailability of certain plant-based nutrients can be lower than animal-sourced alternatives. Here are the primary nutrients to watch:

Vitamin B12 (Cobalamin)

The Issue: Vitamin B12 is crucial for nerve function and red blood cell production. It is primarily found in animal-sourced foods, and while eggs and dairy contain some, the amounts can be insufficient for regular intake, and absorption can be less efficient. Studies show that many lacto-ovo vegetarians have lower B12 serum levels than omnivores, particularly older individuals.
The Solution: Most nutrition experts recommend B12 supplementation for all vegetarians, including lacto-ovo vegetarians, to ensure adequate intake. Reliable sources include fortified foods and simple, daily supplements.

Vitamin D

The Issue: Vitamin D is vital for calcium absorption and bone health, but it's naturally limited in most foods. While milk and eggs are often fortified, relying solely on diet for Vitamin D can be unreliable, especially in regions with limited sun exposure.
The Solution: Spending time in sunlight is the body's primary way to produce Vitamin D. For many, especially during winter months, a supplement is the most reliable way to maintain healthy levels.

Iron

The Issue: Iron is essential for oxygen transport in the blood, and vegetarians may require 1.8 times more iron than omnivores due to the lower bioavailability of non-heme iron from plant sources. High dairy consumption can also inhibit iron absorption.
The Solution: Ensure a diet rich in iron-fortified cereals, lentils, beans, spinach, and tofu. Pairing iron-rich plant foods with Vitamin C-rich foods (e.g., citrus fruits, bell peppers) significantly enhances iron absorption. If dietary measures are insufficient, a supplement may be needed.

Zinc

The Issue: Zinc is crucial for immune function, growth, and wound healing. Some studies suggest lacto-ovo vegetarians might have suboptimal zinc levels, potentially due to the presence of phytates in plant-based foods that inhibit absorption.
The Solution: Good vegetarian sources include legumes, nuts, seeds, and fortified grains. Soaking and sprouting legumes and grains can help improve zinc absorption. A supplement might be necessary if dietary intake is consistently low.

Omega-3 Fatty Acids

The Issue: Omega-3s, particularly EPA and DHA, are important for heart, brain, and eye health. While the vegetarian diet provides ALA from sources like flaxseed and walnuts, the body's conversion of ALA to EPA and DHA is inefficient.
The Solution: An algal oil supplement is the most direct and reliable vegetarian source of EPA and DHA. Increasing ALA intake from foods is also beneficial but should not be relied upon as the sole source of long-chain omega-3s.

Dietary Intake vs. Supplementation for Lacto-Ovo Vegetarians


Nutrient	Primary Dietary Sources for LOVs	Reason for Potential Deficiency	Supplementation Recommendation
Vitamin B12	Dairy, eggs, fortified cereals	Found almost exclusively in animal products; lower levels in dairy and eggs	Strongly recommended
Vitamin D	Fortified milk/eggs, sunlight	Limited natural dietary sources; relies on sun exposure	Often recommended, especially during winter
Iron	Lentils, beans, tofu, fortified grains	Non-heme iron from plants has lower absorption rate	Potentially needed if dietary intake is insufficient or for at-risk groups
Zinc	Legumes, nuts, seeds, dairy	Phytates in plants inhibit absorption	Considered if diet lacks variety or absorption is a concern
Omega-3s (EPA/DHA)	Dairy, eggs (contain some); ALA from flaxseed, walnuts	Inefficient conversion from ALA to EPA/DHA	Often recommended to ensure sufficient EPA/DHA intake

Strategies for a Nutritionally Adequate Lacto-Ovo Diet

Prioritize Nutrient-Dense Foods: Focus on whole foods like colorful fruits and vegetables, whole grains, legumes, nuts, and seeds. These provide a wide spectrum of vitamins, minerals, fiber, and phytochemicals.
Enhance Nutrient Absorption: Pair iron-rich plant foods with Vitamin C sources (e.g., lentils with lemon juice). Consume phytate-rich foods separately from key mineral sources or use techniques like soaking and sprouting to reduce phytate levels.
Consider Fortified Foods: Regularly include fortified breakfast cereals, plant-based milks, and nutritional yeast to boost intake of key nutrients like Vitamin B12 and Vitamin D.
Consult a Professional: Work with a registered dietitian to create a balanced meal plan and determine if specific supplements are necessary based on your individual needs, lifestyle, and health goals.

Conclusion: The Importance of Personalized Planning

While a lacto-ovo vegetarian diet can be a healthy and sustainable choice, it requires careful planning to prevent nutritional gaps. Unlike omnivores, lacto-ovo vegetarians must be particularly mindful of their intake of Vitamin B12, Vitamin D, iron, zinc, and long-chain omega-3 fatty acids. For most, a combination of a varied, well-planned diet, along with regular use of fortified foods and a few key supplements, can ensure all nutritional requirements are met. The need for supplementation is not a sign of a flawed diet but rather a proactive strategy to optimize health. It's not a one-size-fits-all solution, and consultation with a healthcare professional is the best way to tailor a plan to your specific needs.

For more detailed nutritional information and daily recommendations, consult authoritative resources such as the U.S. National Institutes of Health.

Frequently Asked Questions

No, while a lacto-ovo diet includes more nutrients than a vegan one, it still requires careful planning. Key nutrients like vitamin B12, vitamin D, iron, zinc, and omega-3s may require extra attention to ensure adequacy.

Yes, most nutrition experts recommend B12 supplementation. While dairy and eggs contain some B12, the levels are often too low and absorption can be inefficient, leading to lower serum levels compared to non-vegetarians.

To get enough iron, include iron-rich plant foods like lentils, beans, and fortified grains, and pair them with vitamin C sources to boost absorption. In some cases, a supplement may be necessary.

While plant-based ALA is found in flaxseed and walnuts, the conversion to EPA and DHA is limited. The most direct and reliable way to get sufficient EPA and DHA is through an algal oil supplement.

Relying solely on fortified foods for Vitamin D can be unreliable. Sunlight exposure is the body's primary source, but for many, particularly in certain climates, a supplement is the most effective way to ensure adequate levels.

Zinc absorption can be inhibited by phytates found in many plant foods. A varied diet that includes legumes, nuts, and seeds is important, and for those with low intake, a supplement could be considered.

Yes, it is always best to consult with a healthcare professional or a registered dietitian before starting any new supplement regimen. They can help assess your individual needs and create a personalized plan.